Synthesis of cardo poly(arylene ether ketone amide)s by heterogeneous palladium-catalyzed polycondensation of aromatic diiodides, aromatic diamines containing cardo groups and CO

Abstract

New cardo poly(arylene ether ketone amide)s were synthesized by heterogeneous palladium-catalyzed carbonylative polycondensation of aromatic diiodides with ether–ketone linkages, aromatic diamines bearing cardo groups, and carbon monoxide. Polymerizations were conducted in N,N-dimethylacetamide (DMAc) at 120 °C in the presence of a bidentate phosphino-functionalized magnetic nanoparticles-immobilized palladium complex [Fe3O4@SiO2-2P-PdCl2] and 1,8-diazabicyclo[5,4,0]-7-undecene (DBU), yielding a series of cardo poly(arylene ether ketone amide)s with inherent viscosities up to 0.77 dL/g. All the polymers were readily soluble in various dipolar aprotic solvents at room temperature. These polymers showed good thermal stability with the glass transition temperature of 223–289 °C, the temperature at 5% weight loss of 441–464 °C in nitrogen. These cardo poly(arylene ether ketone amide)s could afford transparent, flexible, and strong films by solution-casting with good tensile properties. These polymer films exhibited lower dielectric constants, lower water uptakes, and higher optical transparency. Furthermore, this heterogeneous palladium catalyst can facilely be separated from the reaction mixture by simply applying an external magnet and recycled at least eight times with almost consistent activity.